KR101664893B1 - Method for controlling air conditioning system of vehicle - Google Patents

Abstract

The present invention provides a control method for a vehicle air conditioning system for controlling an air conditioning system mounted on an automobile. (A) comparing the target evaporator temperature calculated based on the air conditioning condition input by the user with the current evaporator temperature transmitted from the evaporator sensor, by the automatic temperature control device; (B) if the current evaporator temperature is less than the target evaporator temperature, determining whether the compressor is operating at a minimum rpm; And (C) when the compressor is driven at a minimum rpm, the fully-automatic temperature regulator transmits a cooling fan down signal to the cooling fan controller.

Description

TECHNICAL FIELD [0001] The present invention relates to a control method for a vehicle air conditioning system,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a control method for a vehicle air conditioning system, and more particularly, to a control method for a vehicle air conditioning system capable of preventing a vehicle from being excessively cooled by using a small amount of electric energy.

An electric vehicle is an automobile that derives its drive energy from electric energy, not from combustion of fossil fuels like existing vehicles. The electric vehicle has no exhaust gas at all and has a small noise. However, the electric vehicle has not been put to practical use due to problems such as heavy weight of the battery and time required for charging. However, recent developments have accelerated due to serious pollution problems and depletion of fossil fuels. As a result, electric cars that have been put to practical use are emerging.

An electric vehicle is equipped with an air conditioning system as in a car powered by fossil energy. 1, the air conditioning system includes a cooling system 60 for cooling the vehicle (indoor), a heating system 70 for heating the vehicle, a full automatic temperature controller (FATC) 70, (HVAC) 80 for controlling the temperature / intensity / direction of the air introduced into the passenger compartment, and the like.

The cooling system 60 includes a compressor 62, a condenser 64, an expansion valve 66, and an evaporator 68. The compressor (62) compresses the low temperature low pressure gaseous refrigerant introduced from the evaporator (68) into the gaseous refrigerant of high temperature and high pressure. The condenser 64 condenses and liquefies the gaseous refrigerant of high temperature and high pressure drawn from the compressor 62. The expansion valve 66 expands the liquid refrigerant introduced from the condenser 64 by the thermal expansion, . The refrigerant passing through the expansion valve 66 absorbs heat from ambient air in the evaporator 68 and is vaporized and then flows into the compressor 62. The main surface air cooled through the heat exchange with the refrigerant in the evaporator 68 is supplied to the vehicle compartment to cool the vehicle.

The heating system 70 includes a pump 74, a heat exchanger 76, and a heating device 72. The heating device 72 heats the working fluid and the heat exchanger 76 heats the heating device 72 and then conveys the heat of the working fluid introduced into the ambient air. The ambient air heated by heat exchange with the working fluid in the heat exchanger (72) is supplied to the passenger compartment to heat the passenger compartment. The pump 74 introduces the working fluid from the heating device 72 into the heat exchanger 76 and returns it from the heat exchanger 76 to the heating device 72. In an automobile driven by a hybrid vehicle or a fossil fuel, an automobile engine is used as a heating device 72, and engine cooling water is used as a working fluid. In the electric vehicle, an electric heater is used as the heating device 72, and water is used as the working fluid.

On the other hand, the electric energy required for driving the compressor (62), the electric energy required for driving the pump (74), and the electric energy necessary for driving the heating device (electric motor Is supplied from the battery 30. Here, the battery 30 is provided to supply electric energy to an electric motor, which is an engine of an electric vehicle, or an electric motor included in an engine of a hybrid vehicle. The electric energy required for driving various doors built in the air conditioner 80 is provided by a fully automatic temperature control device 20 which is supplied with electric energy from the battery 30. [

The fully automatic temperature control device 20 calculates the target evaporator temperature using the air conditioning condition received from the control panel 40 mounted on the center crowbar panel in front of the driver's seat. The fully automatic temperature control device 20 compares the target evaporator temperature with the evaporator temperature received from the evaporator sensor 84 incorporated in the air conditioner 80 (the temperature of the air passing through the evaporator 68) A heating device 72 composed of an electric heater, a pump 74, and a temp door 82 incorporated in the air conditioner 80. [

Specifically, when the evaporator temperature is lower than the target evaporator temperature, the automatic temperature control device 20 raises the temperature (discharge temperature) of the air supplied to the vehicle room by decreasing the rpm of the compressor 62. If the evaporator temperature is lower than the target evaporator temperature even though the rpm of the compressor 62 is the minimum rpm, the fully automatic temperature controller 20 operates the pump 74 and the electric heater 72 to prevent excessive cooling of the passenger compartment And simultaneously drives the tempo door 82 in a warm direction (in the direction of an arrow A) (in the case of an electric vehicle). If the evaporator temperature is lower than the target evaporator temperature even though the rpm of the compressor 62 is at the minimum rpm, the fully automatic temperature controller 20 may move the tempo door 82 in the warm direction In the direction of arrow (A)) (for hybrid cars and fossil fuel powered cars).

However, according to the control method described above, the pump 74, the electric heater 72, and the tempo door 82 must be operated in order to prevent excessive cooling of the passenger compartment when the rpm of the compressor 62 is at the minimum rpm . Further, electric energy must be consumed for the operation of the pump 74, the electric heater 72 and the tempo door 82. Therefore, improvement measures are required.

It is an object of the present invention to provide a control method for a vehicle air conditioning system capable of preventing excessive cooling of a vehicle by using a small amount of electric energy as compared with the related art .

In order to achieve the above object, the present invention provides a control method for a vehicle air conditioning system for controlling an air conditioning system mounted on a vehicle. (A) comparing the target evaporator temperature calculated based on the air conditioning condition input by the user with the current evaporator temperature transmitted from the evaporator sensor, by the automatic temperature control device; (B) if the current evaporator temperature is less than the target evaporator temperature, determining whether the compressor is operating at a minimum rpm; And (C) when the compressor is driven at a minimum rpm, the fully-automatic temperature regulator transmits a cooling fan down signal to the cooling fan controller.

Preferably, the control method for the vehicle air conditioning system further comprises the steps of: (D) comparing the refrigerant discharge pressure, which is the pressure of the refrigerant discharged from the compressor, with the reference refrigerant discharge pressure; And (E) when the refrigerant discharge pressure is lower than the reference refrigerant discharge pressure, lowering the rotational speed of the cooling fan by the cooling fan controller.

In the step (D), the cooling fan controller, which receives the cooling fan down signal, determines whether the coolant discharge pressure of the coolant discharged from the compressor is larger than the reference coolant discharge pressure, And (E) comparing the reference coolant discharge pressure with the reference coolant discharge temperature when the coolant discharge pressure is lower than the reference coolant discharge pressure and the engine coolant temperature is lower than the reference engine coolant temperature , The cooling fan controller may lower the rotational speed of the cooling fan.

On the other hand, when the compressor is driven at a rpm greater than the minimum rpm, the automatic thermostat preferably lowers the rpm of the compression.

According to the present invention, it is possible to prevent an excessive cooling of the vehicle cabin even with a small amount of electric energy compared to the conventional case.

According to the present invention, the stability of the cooling system and the engine of the automobile can be assured.

1 is a block diagram schematically showing a general automotive air conditioning system.
2 is a block diagram schematically illustrating an air conditioning system mounted on an electric vehicle for performing a control method of the air conditioning system for a vehicle according to the present invention.
3 is a flowchart showing a first embodiment of a method for controlling a vehicle air conditioning system according to the present invention.
FIG. 4 is a block diagram schematically illustrating an air conditioning system mounted on a hybrid vehicle or an automobile driven by fossil fuel to perform a control method of the air conditioning system according to the present invention.
5 is a flowchart showing a second embodiment of a control method for a vehicle air conditioning system according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a method for controlling a vehicle air conditioning system according to the present invention will be described in detail with reference to the drawings. It is to be understood that the terminology or words used herein are not to be construed in an ordinary sense or a dictionary, and that the inventor can properly define the concept of a term to describe its invention in the best possible way And should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention.

≪ Embodiment 1 >

In this embodiment, a method of controlling an air conditioning system mounted on an electric vehicle will be described with reference to Figs. 2 and 3. Fig.

The control method of the air conditioning system according to the present embodiment includes the first step (S110) to the fifth step (S150) as shown in FIG.

In a first step S110, a full automatic temperature controller (FATC) 120 compares the target evaporator temperature with the current evaporator temperature. If the current evaporator temperature is lower than the target evaporator temperature, the fully automatic temperature controller 120 performs the second step S120, and if not, performs the first step S110 again.

In order to perform the first step S110, the fully automatic temperature controller 120 calculates the target evaporator temperature in advance based on the air conditioning condition input by the user, and performs a heating, ventilation and air conditioning (HVAC) 180 from the evaporator sensor 184 built in.

The user can input air conditioning conditions (cabin temperature, indoor / outdoor mode, air volume mode, blower number, wind direction mode, etc.) through a control panel (CP) 140 mounted on the center pop- And the control panel 140 transmits the air conditioning condition input from the user to the automatic temperature control unit 120. Then, the fully automatic temperature controller 20 calculates the target evaporator temperature using the necessary ones of the air conditioning conditions received from the control panel 140. The evaporator sensor 184 is installed in the air conditioner 180 and senses the current evaporator temperature, which is the temperature of air passing through the evaporator 168, and then transmits the detected temperature to the fully automatic temperature controller 20.

In the second step S120, the automatic thermostat 120 determines whether the compressor 162 is driven at the minimum rpm. If the compressor 162 is driven at the minimum rpm, the evaporator temperature can not be raised anymore through the rpm control of the compressor 162, so that the fully automatic temperature controller 120 can lower the cooling fan Signal to a cooling fan controller (CFC)

However, if the compressor 162 is driven at a rpm greater than the minimum rpm, the rpm control of the compressor 162 may raise the current evaporator temperature. In this case, the fully automatic temperature controller 120 transmits the control signal to the compressor 162 to reduce the rpm of the compressor 162 (S160). Even when the compressor 162 is driven at a rpm greater than the minimum rpm, the number of revolutions of the cooling fan 152 can be reduced to raise the current evaporator temperature. However, if the compressor 162 is driven at a rpm greater than the minimum rpm because more of the electrical energy may be saved if the rpm of the compressor 162 is reduced than when the number of rotations of the cooling fan 152 is reduced, It is desirable to reduce the rpm of the rotor 162.

In the fourth step S140, the cooling fan controller 150 receives the cooling fan falling signal from the fully automatic temperature controller 120, and outputs the cooling fan falling signal to the cooling fan controller 150, Compare the big and small. Here, the reference refrigerant discharge pressure is a maximum discharge pressure that can prevent damage to the compressor 162 and damage to piping included in the cooling system 160, and is preset by a preliminary test and stored (for example, Lt; / RTI > The cooling fan controller 150 receives the pressure of the refrigerant discharged from the compressor 162 from the discharge pressure sensor (not shown) for performing the fourth step S140 and outputs the reference refrigerant discharge pressure to the memory (not shown) Read from the same storage medium.

If the refrigerant discharge pressure is lower than the reference refrigerant discharge pressure, the cooling fan controller 150 reduces the number of rotations of the cooling fan 152 in the fifth step S150 to prevent excessive cooling of the vehicle. When the number of revolutions of the cooling fan 152 decreases, the temperature of the refrigerant flowing into the expansion valve 166 becomes higher, and the current evaporator temperature rises toward the target evaporator temperature.

However, if the refrigerant discharge pressure is not less than the reference refrigerant discharge pressure, the cooling fan controller 150 maintains the current number of revolutions of the cooling fan 152. If the number of revolutions of the cooling fan 152 is not reduced, the current room temperature is not increased toward the target evaporator temperature, so that the passenger compartment is excessively cooled. Nevertheless, maintaining the number of revolutions of the cooling fan 152 is for the stability of the cooling system 160. That is, if the number of revolutions of the cooling fan 152 decreases while the refrigerant discharge pressure is not less than the reference refrigerant discharge pressure, the refrigerant discharge pressure further increases. In this case, if the compressor 162 is damaged, The present invention can prevent the cooling system 160 from being excessively cooled if the refrigerant discharge pressure is not less than the reference refrigerant discharge pressure, The rotation speed of the cooling fan 152 is maintained.

According to the conventional method of controlling the air conditioning system mounted on an electric vehicle, when it is desired to prevent excessive cooling of the passenger compartment while the compressor 162 is driven at a minimum rpm, the high voltage electric heater 172, the pump 174, The tempdoor 182 must receive electrical energy from the battery 130. [ However, according to the present invention, it is necessary to operate the high voltage electric heater 172, the pump 174 and the tempo door 182 when the compressor 162 is to be prevented from over cooling the car in a state of driving at a minimum rpm The number of rotations of the cooling fan 152 is reduced. Therefore, according to the present invention, a small amount of electric energy is consumed in the case of preventing excessive cooling of the vehicle.

≪ Embodiment 2 >

In this embodiment, a control method of an air conditioning system mounted on a hybrid car or a vehicle driven by fossil fuel will be described with reference to Figs. 4 and 5. Fig. The electric heater 172 included in the heating system 170 of the electric vehicle is replaced by the engine and the radiator 154 for lowering the temperature of the engine cooling water between the cooling fan 152 and the condenser 164 is added Respectively. The engine cooling water that has passed through the heat exchanger 176 of the heating system 170 passes through the radiator 154 and transfers heat to the ambient air and then flows into the pump 174. Also, in a vehicle driven by fossil fuel, the compressor 162 included in the cooling system 160 of the hybrid vehicle receives power from the engine and is driven.

The control method of the air conditioning system according to the present embodiment includes the first step (S110) to the fifth step (S150) as shown in FIG. However, the process up to the fourth step S140a is the same as that described in the first embodiment, and only the process after the fourth step S140a will be described below.

In the fourth step S140a of the present embodiment, the cooling fan controller 150 receiving the cooling fan falling signal from the fully automatic temperature controller 120 controls the pressure (refrigerant discharge pressure) of the refrigerant discharged from the compressor 162, The difference between the discharge pressure and the engine cooling water temperature which is the temperature of the cooling water discharged from the engine 172 is compared with the reference engine cooling water temperature. Here, the reference refrigerant discharge pressure is a maximum discharge pressure that can prevent damage to the compressor 162 and damage to piping included in the cooling system 160, and is preset by a preliminary test and stored (for example, Lt; / RTI > Also, the reference engine coolant temperature is a maximum temperature that can maintain the stability of the engine 172, and is preset in a pre-test and stored in the storage means.

The cooling fan controller 150 receives the pressure of the refrigerant discharged from the compressor 162 from the discharge pressure sensor (not shown) for the execution of the fourth step S140a and sets the temperature of the cooling water discharged from the engine 172 to And receives it from the coolant temperature sensor (not shown). In order to perform the fourth step S140a, the cooling fan controller 150 reads the reference refrigerant discharge pressure and the reference engine coolant temperature ON from a storage means such as a memory (not shown) or the like.

If the coolant discharge pressure is lower than the reference coolant discharge pressure and the engine coolant temperature is lower than the reference engine coolant temperature, the cooling fan controller 150 controls the cooling fan 152 The number of revolutions is reduced. When the number of revolutions of the cooling fan 152 decreases, the temperature of the refrigerant flowing into the expansion valve 166 becomes higher, and the current evaporator temperature rises toward the target evaporator temperature.

However, if the refrigerant discharge pressure is not less than the reference refrigerant discharge pressure or the engine cooling water temperature is lower than the reference engine cooling water temperature, the cooling fan controller 150 maintains the current rotation speed of the cooling fan 152. [ If the number of revolutions of the cooling fan 152 is not reduced, the current room temperature is not increased toward the target evaporator temperature, so that the passenger compartment is excessively cooled. Nevertheless, maintaining the number of revolutions of the cooling fan 152 is for the stability of the cooling system 160 and the engine 172.

If the number of revolutions of the cooling fan 152 decreases while the refrigerant discharge pressure is not less than the reference refrigerant discharge pressure, the refrigerant discharge pressure further increases. In this case, the possibility of damage to the compressor 162 and the possibility of damage to the cooling system 160 If the refrigerant discharge pressure is not less than the reference refrigerant discharge pressure, the stability of the cooling system 160 may be prevented from being prevented from excessive cooling of the passenger compartment 160 The rotation speed of the cooling fan 152 is maintained.

Further, when the number of revolutions of the cooling fan 152 is decreased while the engine cooling water temperature is not lower than the reference engine cooling water temperature, the engine cooling water temperature is further increased. In this case, the engine 172 may be unstable, In the present invention, if the engine cooling water temperature is not lower than the reference cooling water temperature, the stability of the engine 172 is kept higher than the prevention of excessive cooling of the passenger compartment, and the rotation speed of the cooling fan 152 is maintained.

According to the conventional method for controlling the air conditioning system mounted on the hybrid vehicle or the automobile driven by the fossil fuel, when it is desired to prevent the interior of the vehicle from being excessively cooled in a state in which the compressor 162 is driven at the minimum rpm, The electric energy must be consumed for driving the electric motor 182. However, according to the present invention, when the compressor 162 is to be prevented from over cooling the vehicle in a state in which the compressor 162 is driven at the minimum rpm, the tempo door 182 does not need to be driven and the rotation number of the cooling fan 152 is reduced . Therefore, according to the present invention, a small amount of electric energy is consumed in the case of preventing excessive cooling of the vehicle.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is to be understood that the invention may be variously varied and modified within the scope of the appended claims.

120: Full Automatic Temperature Controller (FATC)
130: Battery 140: Control Panel (CP)
150: Cooling Fan Controller (CFC)
152: cooling fan 154: radiator
160: cooling system 162: compressor
164: condenser 166: expansion valve
168: Evaporator 170: Heating system
172: electric heater, engine 174: pump
176: Heat exchanger 182: Temp door
180: Heating, Ventilation and Air Conditioning (HVAC)
184: Evaporator sensor

Claims (4)

A control method for a vehicle air conditioning system for controlling an air conditioning system mounted on an automobile,
(A) comparing the target evaporator temperature calculated on the basis of the air conditioning condition inputted by the user with the current evaporator temperature transmitted from the evaporator sensor, by the automatic temperature control device;
(B) if the current evaporator temperature is less than the target evaporator temperature, determining whether the compressor is operating at a minimum rpm; And
(C) when the compressor is driven at a minimum rpm, the fully automatic temperature control device transmits a cooling fan down signal to the cooling fan controller. The method according to claim 1,
(D) comparing the refrigerant discharge pressure, which is the pressure of the refrigerant discharged from the compressor, with the reference refrigerant discharge pressure, the cooling fan controller having received the cooling fan falling signal; And
And (E) when the refrigerant discharge pressure is lower than the reference refrigerant discharge pressure, lowering the rotational speed of the cooling fan by the cooling fan controller. The method according to claim 1,
(D) The cooling fan controller, which receives the cooling fan falling signal, calculates the difference between the refrigerant discharge pressure, which is the pressure of the refrigerant discharged from the compressor, and the reference refrigerant discharge pressure, and the engine coolant temperature, which is the temperature of the coolant discharged from the engine, Comparing the warm and hot sizes; And
(E) when the coolant discharge pressure is lower than the reference coolant discharge pressure and when the engine coolant temperature is lower than the reference engine coolant temperature, the cooling fan controller decreases the rotational speed of the cooling fan And a control method of the air conditioning system for a vehicle. 4. The method according to any one of claims 1 to 3,
Wherein when the compressor is driven at an rpm greater than the minimum rpm, the automatic temperature control device lowers the rpm of the compressor.

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